Process for refining oils



Patented 19, 1926.

UNITED STATES 1,569,870 PATENT OFFICE- JACQUE c. MORRELL, or C ICACO, ILLINOIS, ASSIGNOR rho UNIVERSAL OIL rROnuC'rs COMPANY, or CHICAGQ, ILLINOIS, A CORPORATION OF sou rn DAKOTA.

PROCESS FOR BEFINING OILS;

NO Drawing.

' carbon oils with a. high sulphur content produced from a raw oil stock having a high sulphur content.

The practice of using a solution of litharge or lead monoxide in sodium hydroxide in conjunction with sulphur for the removal of sulphur compounds in Oils is well known.

However, the mechanism of the reaction has remained obscure, and therefore, variations and im rovements or departures from this method ave been relatively few.

Heretofore, it has been the ractice to agitate a solution of litharge n sodium 'hydroxide (sodium plumbite) with the oil to be, treated, and after. a period of time to add the flowers of sulphur. the suldphur, a precipitate of lead sulphide is forme There is however, a very objectionable feature under such'a method of treatment. Although not generally known, sulphur is quite soluble in hydrocarbon Oils, and no amountwf subsequent washing with water will remove this sulphur dissolved in the Oil. Sulphur in solution in the oil is extremely objectionable, particularly when used as inotor fuel, since it corrodes various metal parts, espeeially brass and copper.

It isthe purpose of tlii'sinvention to eliminate this objectionable feature by the use water, hydro of various compounds of sulphur, and in'particular such substhnces as -calcium, or magnesium sulphide or aluminum sulphide, which though substantiall insoluble in yze when adde to Water forming recipitates of'the corres onding.hy-

. droxldes as well as hydrogen'su phide.

. According to thepreseiit invention, the oil is first preferably treated with sulphuric acid in the, roportion of say, 500 650 pounds of acid per 100. barrels ot foil, sometimes preceded by a water wash. The oil may be agitated in the presence of the acid for 15 With the addition of' .aclean, Water white distillate sweet odor. The oil u on subsequent tests- Application filed August 28,1922. Serial No. 584,870.

to 20 minutes. This isfollowed. by a water wash for 10 or 15 minutes and an alkali wash such as sodium hydroxide or like substances which are used as a base. gallons of 6-l2 B. caustic soda per 100 barrels of oil treated, I have found to he satisfactory. To the oil is then added sodium plumbite (litharge) dissolved in sodium hy- I d roxide or potassium plumbite in the proportion of say, 5 barrels of 16-30? B. caustic containing from 530 pounds of litharge for each 100 barrels of Oil treated. AfterIagL- tation with the plumbite solution, the latter is removed, and although not necessary, in addition it may be desirable to wash out some of the remaining traces of the plumbitc solution from the oil with water before subsequently adding the sulphide.

This removal of the" plumbite solution,

prior to the adding of the sulphide is a wide departure from the usual practice of addin the sulphur while agitating the oil with the plumbite solution. The reason for this is two-fold. First, the sulphide reacts with the plumbite so lution causing unnecessary waste. Second, 1t has been found in connection with the present invention that when a cracked hydrocarbon oil is treated with so dium plumbite solution, an organic compound of lead soluble in oil is formed.

Upon the addition of a small amount of 11 ide of calcium magnesium or aluminum, .or other metallic sulphide materials in the proportion of say, 4 to20 pounds per '100 barrels of oil, which hydrolyze in water,

a precipitate of lead sulphide is immediately produced.

'The1ead.su1phideis allowed to settle and may even be assisted by special treatment. The sulphide material lswithdrawn from theoil, and the oil is subsequently water washed to remove any traces of the remaining sulphide precipitate or sulphide solution. Aft? er this cleanin Operation, the oil is distilled,

preferably wit the use of steam, reducing high sulphur bearing oils with uniformly 11 0 10o aving a 4 I claim as my invention:

A step in a process for refining and puri' tying mineral oil, consisting in subjecting the oil to the action of alkali metal plumbitc in Water solution, in then removing substantially all the alkali metal plumbite solution from the oil, in then treating the freed oil with a metallic sulphide capable of hydrolyzing in Water to complete the reaction of the plnmbite solution, and in then removing the separated precipitate and sulphide compounds.

. JACQUE C. MORRELL. 

